Good network card for servers? + how do I tell if this CPU is compatible?

[Chase]

I currently run a PC I turned into a server, it's running Windows Server 2008.. Gave it 512 MB RAM already, and later I will buy this and 1 GB RAM... But how can I tell if this CPU is compatible with my motherboard? And I'd like to pick a NIC card thats atleast under $100 dollars.